The Big Apple manhwa volume 1 features story by Harusari and art by Hodot.

Joachim has a deadly secret: he's a hitman for the SIA (the “Secret Intelligence Agency”): a covert organization whose operatives possess special abilities. Working in the shadows, Joachim is a trained professional assigned dangerous missions that he executes to perfection. Yet, despite his aptitude for the job, Joachim hates it! He's constantly caught up in daydreams about quitting his risky life and trading it all for peaceful bliss with his handsome and generous lover, Juergen Eisler. But quitting the Agency is easier said than done.

When Joachim's latest mission goes awry, he determines to do whatever is necessary to keep Juergen safe—even if it means breaking off their relationship and going dark. Except Juergen isn't ready to give him up so easily.